Pressure gauge



y 1931- J. w. MOTHERWELL I 1,814,092

PRESSURE GAUGE Original Filed May. 23, 1924 @vvor I Patented July 14, 1931 UJQEPH ,w- M THERWEL r 'MELRQSE-1YIA$ACHU5E;T;T.$,ASSIGNQR To. THE ASHTON 'vewncommmnor CAMB IDGE ,lvxa acnu masaconromrx or Messecnnsm'rs Originalhpplieation filed May 23, 1924,

Theprincipal object of myinventionis-to provide a pressure gauge having great accu-,

particularly in cases where considerable Strength and considerablefiexiblhty are de- 5 sirable, especially for large gauges and where 'are to be indicated, or inother words where Y gavi'de ranges between increments of pressure sible with one tube and an advantage is that,

although the strength is increased, accuracy and efficiency are maintained.

In the drawings Figure 1 is a front elevation of a gauge embodying my invention, the dial and outer parts being omitted; and

Figure 2 is a side elevation of the same but withoutsome of the parts.

Gauge casing A has within it socket a leading from the source of pressure to four Bourdon spring tubes each having one end fixed to the socket and each having a closed movable end, that is, there is no conduit for the passage of pressure from onemovable end to any other movable end. Two of these springs B and B are concentric and have their'movable ends rigidly connected by a head B? having pivotal connection with bracket B, the latter having also pivotal connection with head B which rigidly connects together the movable ends of tubes B and 13. From bracket B depends lug B pivotallyconnected to link B which has slotted connection with arm B of a bell crank lever which is pivoted to an extension of socket a, the other arm B being pivotallyrconnected to link B", which may be adjustable if desired, link B being pivotally connected to the rocking segment B which, as is well'known in the art, operates the indicating pointer.

PRESSURE GAUGE Serial No. 715,399. Divided and thisapplication filed October 1, 1929. Serial I To 396 ,55 6

The-tubes B and B may move as a uni separate from the tubes B and B I The motion of the ends of aconcentric pair ofithe tubes is determinedibythe pressure :within the tubes, bythe. elastic constants of the tubes and by the. connecting head.

The centersline'of'the link B isvparallel to'the tangent to the locus of the movable end deflection at a point midway between the pointsIot' no load andmaximum load. The movable ends of the tubes all occupy normally substantially the same positionlnadially of the gauge and are actuated by thesame pressure with the consequence that the a movable ends will tend to move outwardly in such manner that v the center line of j the "link will be parallel to the-tangent. above-referred to whereas; if; the. tubes are of substantially Idif ferent arcuate length, their movable endswill tend. to move outwardly inFvarying directions and each movable end will consequently. tend tohinder. or impede-the independent action 'of the other movable ends. This independent actionis an advantage. of the=parallelism of the link Breferredto-above andlanotherimportant -.advantagethereof is that it contributestoobtaining the, benefit of. the maximum travel of. they tubes;

WhatI, claimis v '1. A'device of the character described comprising a pluralityof concentric areuate spring tubes to be connected with the same source of pressure {and each having .azfixed end and a closedjmovable end, eaeh;movable end beingclosed also with relation to :the Other movable endor-ends'pahead rigidly connectingthe movable ends of-said plurality; a-rockingelementfor operating an indicator; uandwmeans operatively connecting said head" and said rocking. element.

-2. A device of the character described com prising a plurality of concentric arcuate spring tubes to beconnected withthe same source of'pressureand each havinga fixed end and a-closedgmovable end ahead rigidly connecting the movable ends. of saidplurality; another plurality of concentric .spring t-ubesconnected with said .s'ource of pressure and-eachhaving-afixed endiand a-closed-movable. and; ano her mad rigidly meanest-ing the movable ends of said other plurality; a rocking element for operating an indicator; and means operatively connecting said heads and said rocking element,

3. A device of the character described comprising a plurality of concentric arcuate spring tubes, all to be connected with the same source of pressure and each having a fixed end and a closed movable end, each movable end being closed also with relation to the other movable end or ends, said movable ends being normally substantially in line radially of the device; a head rigidly connecting the movable ends of said plurality; a rocking element for operating an indicator; and means operatively connecting said head and said rocking element.

4. A device of the character described comprising a plurality of concentric arcuate spring tubes, all to be connected with the same source of pressure and each having a fixed end and a closed movable end, each movable end being closed also with relation to the other movable end or ends, said tubes having their dimensional characteristics relatively so proportioned that their movable ends remain substantially in the same position radially with relation to the center of the device throughout the movement of the tubes; a head rigidly connecting the movable ends of said plurality; a rocking element for operating an indicator; and means operatively connecting said head and said rocking element.

' 5. A device of the character described comprising a plurality of concentric arcuate spring tubes to be connected with the same source of pressure and each having a fixed end and a closed movable end, each movable end being closed also with relation to the other movable end or ends; a head rigidly connecting the movable ends of said plurality; a rocking element for operating an indicator; and means operatively connecting said head and said rocking element and including a link the center line of which is substantially parallel to the tangent to the locus of the movable end deflection at a point midway between the points of no load and maximum load.-

6. A device of the character described comprising a plurality of concentric arcuate spring tubes. to be connected with the same source of pressure and each having a fixed end and a closed movable end, each movable end being closed also with relation to the other movable end or ends; a head rigidly connecting the movable ends of said plurality; a rocking element for operating an inclicator; and means operatively connecting said head and said rocking element, said means including a plurality of elements movable with relation to each other.

7. A device of the character described comprising a plurality of concentric arcuate spring tubes to be connected with the same source of pressure and each having a fixed end and a closed movable end, each movable end being closed also with relation to the other movable end or ends; a head rigidly connecting the movable ends of said plurality; a rocking element for operating an indicator; and means operatively connecting said head and said rocking element, said means including a plurality of elements movable with relation to each other, one of said plurality of elements being a link, the center line of which is substantially parallel to the tangent to the locus of the movable end detlection at a point midway between the points of no load and maximum load.

8. A device of the character described comprising a plurality of concentric arcuate spring tubes to be connected with the same source of pressure and each having a fixed end and a closed movable end; a head rigidly connecting the movable ends of said plurality; another plurality of concentric spring tubes connected with said source of pressure and each having a fixed end and a closed movable end; another head rigidly connecting the movable ends of said other plurality; a

rocking element for operating an indicator; and means operatively connecting said heads and said rocking element, said means including a plurality of elements movable with relation to each other.

JOSEPH W. MOTHERWELL. 

